# Copyright (c) 2014-2016 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test gettxoutproof and verifytxoutproof RPCs."""

from test_framework.messages import CMerkleBlock, FromHex, ToHex
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import assert_equal, assert_raises_rpc_error, sync_txindex
from test_framework.wallet import MiniWallet


class MerkleBlockTest(BitcoinTestFramework):
    def set_test_params(self):
        self.num_nodes = 2
        self.extra_args = [
            [],
            ["-txindex"],
        ]

    def run_test(self):
        miniwallet = MiniWallet(self.nodes[0])

        chain_height = self.nodes[1].getblockcount()
        assert_equal(chain_height, 200)

        txid1 = miniwallet.send_self_transfer(from_node=self.nodes[0])["txid"]
        txid2 = miniwallet.send_self_transfer(from_node=self.nodes[0])["txid"]

        # This will raise an exception because the transaction is not yet in a
        # block
        assert_raises_rpc_error(
            -5, "Transaction not yet in block", self.nodes[0].gettxoutproof, [txid1]
        )

        self.generate(self.nodes[0], 1)
        blockhash = self.nodes[0].getblockhash(chain_height + 1)

        txlist = []
        blocktxn = self.nodes[0].getblock(blockhash, True)["tx"]
        txlist.append(blocktxn[1])
        txlist.append(blocktxn[2])

        assert_equal(
            self.nodes[0].verifytxoutproof(self.nodes[0].gettxoutproof([txid1])),
            [txid1],
        )
        assert_equal(
            self.nodes[0].verifytxoutproof(self.nodes[0].gettxoutproof([txid1, txid2])),
            txlist,
        )
        assert_equal(
            self.nodes[0].verifytxoutproof(
                self.nodes[0].gettxoutproof([txid1, txid2], blockhash)
            ),
            txlist,
        )

        # Get the change from txid2
        txin_spent = miniwallet.get_utxo(txid=txid2)
        tx3 = miniwallet.send_self_transfer(
            from_node=self.nodes[0], utxo_to_spend=txin_spent
        )
        txid3 = tx3["txid"]
        self.generate(self.nodes[0], 1)

        txid_spent = txin_spent["txid"]
        txid_unspent = txid1  # Input was change from txid2, so txid1 should be unspent

        # Invalid txids
        assert_raises_rpc_error(
            -8,
            "txid must be of length 64 (not 32, for"
            " '00000000000000000000000000000000')",
            self.nodes[0].gettxoutproof,
            ["00000000000000000000000000000000"],
            blockhash,
        )
        assert_raises_rpc_error(
            -8,
            "txid must be hexadecimal string (not"
            " 'ZZZ0000000000000000000000000000000000000000000000000000000000000')",
            self.nodes[0].gettxoutproof,
            ["ZZZ0000000000000000000000000000000000000000000000000000000000000"],
            blockhash,
        )
        # Invalid blockhashes
        assert_raises_rpc_error(
            -8,
            "blockhash must be of length 64 (not 32, for"
            " '00000000000000000000000000000000')",
            self.nodes[0].gettxoutproof,
            [txid_spent],
            "00000000000000000000000000000000",
        )
        assert_raises_rpc_error(
            -8,
            "blockhash must be hexadecimal string (not"
            " 'ZZZ0000000000000000000000000000000000000000000000000000000000000')",
            self.nodes[0].gettxoutproof,
            [txid_spent],
            "ZZZ0000000000000000000000000000000000000000000000000000000000000",
        )
        # We can't find the block from a fully-spent tx
        assert_raises_rpc_error(
            -5,
            "Transaction not yet in block",
            self.nodes[0].gettxoutproof,
            [txid_spent],
        )
        # We can get the proof if we specify the block
        assert_equal(
            self.nodes[0].verifytxoutproof(
                self.nodes[0].gettxoutproof([txid_spent], blockhash)
            ),
            [txid_spent],
        )
        # We can't get the proof if we specify a non-existent block
        assert_raises_rpc_error(
            -5,
            "Block not found",
            self.nodes[0].gettxoutproof,
            [txid_spent],
            "0000000000000000000000000000000000000000000000000000000000000000",
        )
        # We can get the proof if the transaction is unspent
        assert_equal(
            self.nodes[0].verifytxoutproof(self.nodes[0].gettxoutproof([txid_unspent])),
            [txid_unspent],
        )
        # We can get the proof if we provide a list of transactions and one of
        # them is unspent. The ordering of the list should not matter.
        assert_equal(
            sorted(
                self.nodes[0].verifytxoutproof(
                    self.nodes[0].gettxoutproof([txid1, txid2])
                )
            ),
            sorted(txlist),
        )
        assert_equal(
            sorted(
                self.nodes[0].verifytxoutproof(
                    self.nodes[0].gettxoutproof([txid2, txid1])
                )
            ),
            sorted(txlist),
        )
        # We can always get a proof if we have a -txindex
        sync_txindex(self, self.nodes[1])
        assert_equal(
            self.nodes[0].verifytxoutproof(self.nodes[1].gettxoutproof([txid_spent])),
            [txid_spent],
        )
        # We can't get a proof if we specify transactions from different blocks
        assert_raises_rpc_error(
            -5,
            "Not all transactions found in specified or retrieved block",
            self.nodes[0].gettxoutproof,
            [txid1, txid3],
        )
        # Test empty list
        assert_raises_rpc_error(
            -5, "Transaction not yet in block", self.nodes[0].gettxoutproof, []
        )
        # Test duplicate txid
        assert_raises_rpc_error(
            -8,
            "Invalid parameter, duplicated txid",
            self.nodes[0].gettxoutproof,
            [txid1, txid1],
        )

        # Now we'll try tweaking a proof.
        proof = self.nodes[1].gettxoutproof([txid1, txid2])
        assert txid1 in self.nodes[0].verifytxoutproof(proof)
        assert txid2 in self.nodes[1].verifytxoutproof(proof)

        tweaked_proof = FromHex(CMerkleBlock(), proof)

        # Make sure that our serialization/deserialization is working
        assert txid1 in self.nodes[0].verifytxoutproof(ToHex(tweaked_proof))

        # Check to see if we can go up the merkle tree and pass this off as a
        # single-transaction block
        tweaked_proof.txn.nTransactions = 1
        tweaked_proof.txn.vHash = [tweaked_proof.header.hashMerkleRoot]
        tweaked_proof.txn.vBits = [True] + [False] * 7

        for n in self.nodes:
            assert not n.verifytxoutproof(ToHex(tweaked_proof))

        # TODO: try more variants, eg transactions at different depths, and
        # verify that the proofs are invalid


if __name__ == "__main__":
    MerkleBlockTest().main()
